I've been on both sides of the language barrier. I've run PUGs with 5 English speakers and one Chinese, and I've been the only English speaker in a Chinese group. Always nothing but respect and support, which I find very typical in most PUGs on Sarlona. If you want to call someone out for being a poor player, that is your call and you deal with the consequences. Attacking someone's ethnicity or language is cowardly and juvenile; there is no place for it in this or any other game. Check that - there is no place for it anywhere.
Based on my recent high level pugging experiences, I have a reasonable idea on what guild this player is from and a pretty good beat on the player name. Would someone be so kind as to drop me a PM with the name so I can confirm my suspicions?
Finally, to the OP - I've never been in a game situation where I was attacked racially, so I have no idea how you must feel. I can tell you the standard things - let it go, not everyone is like this, you are always welcome in my groups - but not of that changes how you feel. I sincerely hope that you are able to continue to enjoy this game and that this incident has not ruined this game for you. Hope to see you around, and good luck moving forward.